* docs(toh-6/ts): minor edits and enhancements
Changes to prose:
- Complete TODO item of displaying `heroes.component` errors.
- Mainly copyedits.
- Add of blocks statements so that prose can be used on Dart side.
- Show excerpt and briefly explain of changes (previously missing):
- `app/hero-detail.component.html`
- `app/heroes.component.ts` error handling
- Add missing file to changed/added files listing and makeTabs
- `toh-6/ts/app/in-memory-data.service.ts,
- `toh-6/ts/sample.css`
Code changes:
- Mainly copyedits
- Renamed `heroes.component.ts` `delete` to `deleteHero` to match
naming of other methods
* remove unnecessary change relative to toh-5
